#!/usr/bin/env node


const {Readable}=require('stream');

class MyReadable extends Readable{
  constructor(){
    super();
  }

  _read(){
    this.push(String.fromCharCode(this.#c++);
    if(this.#c>'z'.charCodeAt(0))this.push(null)
  }
}

#c='a'.charCodeAt(0);
rs.pipe(process.stdout);
